Blanch fava beans in a pot of salted boiling water just until tender, about 1 minute. Transfer to an ice-water bath. Blanch asparagus in a pot until just tender, 2 to 3 minutes ; transfer to ice-water bath. Drain vegetables. Remove outer skin from fava beans (you should have 1 cup). pat asparagus dry.

Heat a large skillet over medium-high. Swirl in oil, then add garlic and fava beans and season with salt. Cook, stirring frequently, until garlic is softened, 2 minutes. Remove from heat. Transfer beans to a plate with a slotted spoon. Let skillet cool slightly, then whisk lemon juice into oil in skillet; season with salt and pepper. (Add more oil if dressing is too tart.) Add asparagus; toss to coat with dressing.

Combine almonds and lemon zest in a small bowl. Transfer asparagus to a platter, top with fava beans, and drizzle remaining dressing in skillet over top. Sprinkle with almond-zest mixture and serve.